Electric switch



May 13, 1930. w. J. TRAXEL 1,758,629

ELECTRIC SWITCH Filed 001:. 5, 1923 Mani 07: Ml/[c2772 Lfamaa Ema! with mercury tube switches Patented May 13, 1930 UNITED STATES PATENT OFFICE WILLIAM JAMES TRAXEL, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO THE LIQUID CARBONIC CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE ELECTRIC SWITCH Application filed October 5, 1923. Serial No. 666,661.

This invention relates to improvements in electric switches and its purpose is to provide improved means for controlling the action of an electric switch and preventing'the accidental opening or closing thereof. The invention is particularly useful in connection in which the electrical contacts are connected and disconnected by the movement of the mercury when the tube is tilted and the improvement is adapted to prevent the tilting of the mercury tube until a predetermined pressure is applied on the switch operating member. Other objects and advantages of the invention will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawings Fig. 1 shows a side elevation of the switch with the front cover of the switch casing removed; Fig. 2 shows a sectional view on the line 2-2 of Fig. 1; Fig. 3 shows a sectional view on the line 3-3 of Fig. 1.

The improved switch comprises a sheet metal box or casing 10 having a rear wall 10*, upper and lower walls 10", side walls 10 and flanges 10 projecting downwardly and upwardly from the front edges of the upper and lower walls, respectively. .The switch comprises an operating lever 11 which projects through an opening 12 in one of the side walls 10 of the casing, being provided at its outer end with a looped portion 11 which forms a handle for operating the switch. The lever 11 is provided between its ends with an enlarged hub, member 13 which is pivotally mounted on a bolt 14 extending through an aperture in the rear wall 10 of the casing and secured in fixed position thereon by means of the nuts 15. A spring clip 16 is mounted on the bolt 12, the transverse bar 16 thereof being. located between the head of the bolt and the hub 13 of the operating lever. The spring clip 16 comprises two resilient arms 16 which are curved adjacent their outer ends to conform to the contour of the cylindrical tube 17 which is closed at its ends and insulated from the spring clips by a surrounding layer of insulating material 18. The tube 17 is partly filled with a suitable quantity of mercury or other equivalent material 19 and when the tube is properly positioned the mercury is adapted to form a connection between the electric terminals 20 and 21 which are brought in through the ends of the tube. The terminals 20 and 21 are connected to lead wires 22 and 23, respectively, which are supported in apertures formed in the insulating material 18 and which are connected at their other ends to the binding screws 24, 25, respectively, mounted on the terminal plates 26. These plates are mounted on a bar 27 of insulating material which is secured to the rear wall 10 of the casing by means of screws 28 and the plates are connected by binding screws 29 to the lead wires 30 which are brought in through suitable openings in the top wall of the casing.

For the purpose of controlling the tilting of the switch lever 11, this lever is provided with a projection 11 extending beyond the tube 17 between the arms of a substantially U-shaped spring clip 31 which is secured to the bottom wall 10 of the casing by means of a bolt 32 and a nut 33. The upwardly extending arms of the spring clip are provided with opposite V-shaped projections 31 which extend inwardly into contact with each other. When the switch lever is in the position shown by full lines in Fig. 1, it can not be depressed to effect the tilting of the mercury tube 17 until suflicient pressure has been applied thereto to .overcome the resiliency of the arms of the spring clip 31 whereupon the arms separate and the projection 11 snaps upwardly to its upper position, shown by dotted lines in Fig. 1. The improvement thus insures a quick action of the switch when the predetermined pressure is applied in addition to preventing the accidental operation of the switch so that the circuit is opened or closed within the mercury tube very suddenly and all danger of arcing is prevented. The parts of the switch are normally inclosed by a cover which is secured to the flanges 10 of the casing.

Although one embodiment of the invention has been shown and described for purposes of illustration, it will be understood that it may be constructed in various other forms without de arting from the scope of the appended claims.

I claim:

1. An electric switch comprising a casing, a lever pivotally mounted in said casing and having a handle extending 'from said casing and a projecting extremity on the opposite side of its pivotal point from said handle, a mercury tube switch mounted on said lever to tilt therewith, flexible conductors connected to the contacts of said mercury tube switch, and a pair of spring clips secured to said casing and having parts directed inwardly toward each other for engagement with said projecting extremity of said lever, said extremity being adapted to be movedbetween the inwardly projecting portions of said spring clips when pressure is exerted on said handle and be retained by said spring clips on either side of said inwardly projecting parts.

2. An electric switch comprising a casing, a lever pivotally mounted in said casing and having a handle extending therefrom and a projecting extremity on the opposite side of its pivotal point from said handle, a mercury tube switch mounted on said lever with substantially equal parts thereof extending on opposite sides of said pivotal point, fiexible conductors connected to the contacts of said mercury tube switch, and a pair of spring clips secured to said casing and having parts directed inwardly toward each other for engagement with said projecting extremity of said lever, said extremity being adapted to move between inwardly projecting portions of said spring clips when pressure is exerted on said handle and to be retained by said spring clips on either side of said inwardly pro ecting parts.

WILLIAM JAMES TRAXEL. 

